1. Field of the Invention
The present invention relates to a DNA that encodes the transcription factor BP1, a vector containing the DNA and a host cell containing the DNA. The invention also relates to an antisense DNA or RNA to the DNA encoding BP1, methods for treating sickle cell anemia by administering an effective amount of BP1, and methods for screening for acute myeloid leukemia, acute lymphocytic leukemia, and breast cancer.
(In the provisional application, the transcription factor BP1 was sometimes called “BP1/Dlx9” or “BP1/D1x9”. Herein, for greater clarity, the transcription factor is simply referred to as “BP1”.)
2. Description of the Related Art
Expression of globin genes in the β-globin cluster is restricted to erythropoietic cells, with five different genes expressed during embryonic (ε), fetal (Gγ and Aγ) and adult (δ and β) development. Transcriptional activation of globin genes occurs not only by binding of transcriptional activator proteins to the promoter of the gene being activated, but also by a regulatory element located 6–18 kb upstream of the β-globin cluster, the Locus Control Region (LCR) (See, for example, Berg, P. E. and A. N. Schechter. 1992. Molecular genetics of disorders of hemoglobin. In T. Friedmann (ed), Molecular Genetic Medicine, Academic Press, San Diego, Forrester, W. C., C. Thompson, J. T. Elder, and Groudine, M. 1986. A developmentally stable chromatin structure in the human β-globin gene cluster. Proc. Natl. Acad. Sci., USA 83: 1359–1363; and Tuan, D., W. Soloman, Q. Li, and I. M. London, 1985. The “β-like-globin” gene domain in human erythroid cells. Proc. Natl. Acad. Sci. USA 82: 6384–6388.). Sequential activation of the β-globin cluster genes during ontogeny must be countered by repression of the globin genes inactive during a given developmental stage. Repression is caused by binding of repressor proteins to promoter/upstream DNA and, in the case of the adult β-globin gene, is probably also due to lack of activation by the LCR (see, for example, Crossley, M. and S. H. Orkin. 1993. Regulation of the β-globin locus. Curr. Opinion Gen. Dev. 3: 232–237.). While much is known about transcriptional activators that bind to DNA sequences near the β-globin gene, little is known about the proteins that repress its transcription.
As discussed below, BP1 is shown to bind to two silencer DNA sequences upstream of the β-globin gene and therefore, there is strong evidence suggesting that BP1 protein is a repressor of the β-globin gene. The present invention provides for a DNA sequence that encodes BP1, and methods of using information derived from knowledge of the DNA sequence to screen for conditions such as breast cancer, acute myeloid leukemia and acute lymphocytic leukemia. The DNA sequence was found to be closely related to two other human genes, DLX4 and DLX7, described in Quinn, L. M., B. V. Johnson, J. Nicholl, G. R. Sutherland, and B. Kalionis. 1997. Isolation and identification of homeobox genes from human placenta including a novel member of the Distal-less family, DLX4. Gene 187: 55–61 and Nakamura S, Stock D W, Wydner K L, Bollekens J A, Takeshita K, Nagai B M, Chiba, Kitamura T, Freeland T M, Zhao Z, Minowada J, Lawrence J B, Weiss K B, and Ruddle F H. Genomic analysis of a new mammalian Distal-less gene: Dlx-7. Genomics 1996; 38: 314–324.
Survival rates for many types of cancers correlate with early detection and treatment. Further, it is helpful to monitor ongoing cancer treatments to determine effectiveness. Accordingly, there is a continuing need for reliable cancer cell screening methods. One method of screening is to detect and monitor the expression of genes that are overexpressed or underexpressed in particular types of cancer cells, in comparison to normal cells. Detection techniques and particular markers have been disclosed, for example, in the following U.S. patents, incorporated herein by reference: U.S. Pat. No. 5,776,683 to Smith et al; U.S. Pat. No. 5,965,409 to Pardee et al; U.S. Pat. No. 6,037,129 to Cole, et al; U.S. Pat. No. 5,677,125 to Holt, et al; U.S. Pat. No. 6,004,756 to Watson, et al; U.S. Pat. No. 5,994,062 to Mulshine, et al; U.S. Pat. No. 5,700,927 to Zon, et al; and U.S. Pat. No. 5,981,218 to Rio et al.
Because no marker or method of screening is completely reliable, there is a continuing need in the art for additional genetic markers. In particular, there is a continuing need for genetic markers for identifying breast cancer, acute myeloid leukemia and acute lymphocytic leukemia. The present invention overcomes this problem in the art by providing DNA BP1 compositions and methods for screening for breast cancer, acute myeloid leukemia and acute lymphocytic leukemia.
The problem also exists in the art of lack of information regarding repression of the β-globin gene. As discussed below, there are medical conditions such as sickle cell anemia that can be treated by repressing the expression of β-globin and the present invention, provides for the production of BP1, a putative β-globin repressor.